studiot

Good morning and welcome to ScienceForums, jerin. You really do need to provide sufficient information about your question. It only wastes other people's time finding this out if you don't. Are you asking an engineering about 'emptying' a gas cylinder? Or are you draining a liquid? Or is this cylinder an aerosol can? or what?

Was your question answered? You did say you are trying to understand magnetism.

You have the wrong 'fallacy' What did you make of my experiment?

Franky, Please put your comments outside the quote box or this happens. Were you not going to say any more?

I haven't watched the video, but I hope he did not offer the common fallacy. Magnetic fields do not push by themselves. Experiment. Place an ordinary bar magnet on a slippery table surface. Now bring the north pole of another bar magnet towards the north pole of the bar magnet. What do you observe to happen? What do you deduce from this observation?

Well I think Heaven is the place where no one has to obey any of the rules, ever. So ScienceForums must be 'heaven'. I say that because the rules seem to have gone out of the window in this thread. This is a place for Science. Enough is Enough.

Since we have reached the point of offerening definitions in this discussion please define what you mean by "subfield" exactly for me. What, for instance, are the characteristics that distinguish it from a 'field' ?

The Postman : David Brin Lord of the Flies : William Golding On the beach : Neville Shute

Greybeard https://en.wikipedia.org/wiki/Greybeard

I shouldn't worry about angular momentum until you have got the basics sorted. The n I referred to comes out of the wash as the principal quantum number. When you solve the simple wave equation for a time independent solution you do this by a method known as 'separation of the variables'. You look for a solution of the form y(x,t) = g(x)f(t) so that you have two separate functions (one of x and one of t) multiplied together. Your original sine had x and t mixed up in the sine, which won't as you can't remove the time dependence.

Where did L come from?

OK so let's start at the beginning. Both the simpler wave equation and the Schroedinger equation are (second order) differential equations connecting space and time via another variable that has a connection to each. In the case of the wave equation, that's all it does. Also its third 'connection variable' can be directly related to some physical property such as displacement (the y in your equation) or pressure or stress. On the other hand the Schroedinger equation not only includes energy but also introduces a connection variable that is not physical property. This variable is often referred to as a 'probability density' and has the units of the reciprocal of the square root of metres in one dimension. I see that swansont has referred to your itnegral and boundary conditions. A second order differential equation cannot be solved without boundary conditions as the two integrations needed introduces arbitrary constants or functions which are determined by the boundary conditions. I am sure I derived Schroedinger from the wave equation here at SF not too long ago with full explanation of all this. And I thought it was for you but perhaps it was for someone else. The reason for my question about the sine wave is that. 1) It is periodic. 2) It is bounded. A function like this one would not be acceptable as a solution. Because although it repeats itself periodically, it also goes off to infinity and is discontinuous. All travelling waves are time dependent by definition. A time independent wave is another name for a stationary or standing wave.

What do you know about the sine function, because you are missing something from your posted equation ? That something is usually given the synbol n.

No.

This could involve you in a debate as to whether bitcoin is material or non material.

One of the moderators here is/ was a top notch lawyer. And a very keen mind to boot. But if you don't want to put in the effort I'm sorry but you will have to take things on trust, rather than understand them.

A good way to put it. +1 The way to understabding is to do it in stages, just like modern relativity was developed in stages. To start here is an experiment you can perform for yourself. I have located a point P1 at (X1 , Y1) on an XY plot as shown by the dotted lines to the axes X and Y. Then I have drawn some rotated axes X' and Y' (the dashed axis lines) and again located the coordinates of P1 , now with different values X1' and Y1'. This is shown by the dash-dot chain lines. For the experiment introduce a second point P2 with its own coordinates, as shown. Now either (or better both) measure or calculate the distance between P1 and P2 in both the XY and the X'Y' coordinates. You should be able to convince yourself they are the same. For reference the formulae are [math]{d_{XY}} = \sqrt {{{\left( {{X_2} - {X_1}} \right)}^2} + {{\left( {{Y_2} - {Y_1}} \right)}^2}} [/math] and [math]{d_{X'Y'}} = \sqrt {{{\left( {{X_2}' - {X_1}'} \right)}^2} + {{\left( {{Y_2}' - {Y_1}'} \right)}^2}} [/math] The coordinates themselves measure position, of a single point. You need two points to define (measure) a distance. Both position and distance are properties. Much of modern Physics involves the search for properties that are the same in different coordinate systems. Such properties are called invariants. If you are still interested, we can apply this to time in another post.

I posted an encouraging "go on" because I couldn't make a connection to the extract from my post which you replied to. I am now even more mystified than ever by your response. Well that is only one definition of 'seeing' and contrary to the Scientific Dictionary definition, coinciding with the usage by the John Cutherber camp. However I am glad you joined the fray because I was hoping to ask someone who knows vastly more bioscience than I to pass comment on creatures which are born blind but have eyes which they later develop sight in. I have always stated that there is more than one usage of see. Yes I agee we can see light. One distinct usage I also agree with those who say we can see objects, in the sense of a Cahron Y's reconstruction. Another distince usage I can also see difficulties with both those usages in certain circumstances, if either are presented as the only definition. That is why I have constantly maintained "It's complicated" and provided numerous examples. Here is one for optical illusions. What do you 'see' ?

Go on ?

The OP presumably had a reason for that statement, though we will never know what that reason was. So no, it is not outside the scope of the OP at all. 'Seeing' is a complicated process, as is 'invisibility/visibility' and they not the same thing. I can see with my eyes a certain something that is invisible , but I cannot see it in my minds eye in my brain. We can overcome this by looking at a static picture for as long as we need. Again this is still the basis of many optical illusions.

So there is more than one way of seeing for humans.

If this were true then how would you account for the fact that two humans can look at something and 'see' two different things? This fact is much used in optical illusions.

Isn't ultra modern computing a great step forwards? I can select any size I want (although I shouldn't need to bother) in my Tex editor. When I paste it into the useless new SF editor, those instructions are stripped out. So whatever size I order I get the same sized squashed pizza on my plate (sorry symbols on my screen). But thanks very much for trying, it is not your fault.

I don't think I disagree with anything dru said. My comment was directed at minimal cost/effort solutions. String Junky has exactly the right comment that you breathe out a considerable amount of moisture. But more still comes out of the air as the temperature drops. After standing in the drive for a while, my car often has condensation on the inside of the windows in the current weather The absorbtion and retention process does not only apply to mould substance, it also applies to fabrics, such as covers. In particular it applies to the fabric inner linings of vehicles. The moisture builup in these can easily go stale. All the problems are exacerbated by the confines of the space. So yes a dehumidifier will help. You can also get roof mounted ventilators/ extractors that are often fitted to commercial vehicles that will help a great deal and be better than cracking the windows open a tad. Some of these extractors do not need power, which may be a bonus for you. Boats often have wind powered extractors and small generators, most useful whne they are moored at night. You haven't said if you are on a site with a mains electricity supply. Anything you can do to keep the air moving will help and as I said just a small temperature lift will keep the internal air form a continual condensation cycle.

But I gave you solution in 2nd post.. Except that I had already tried that and it doesn't work. I already said that something here seems to overide the (enhanced) size setting I choose. Thanks anyway. What I don't know is how others see the Tex I am posting but for me it is so small that is muddles up fractions for instance.